I took a class in Thai cooking at the New School of Cooking in Culver City which I really enjoyed. A friend took the entire professional series there and thought it was excellent. They have a wide variety of classes.

I have no personal experience with them, so this isn't my personal recco. But, sparing the back story, this guy seems to be a mensch, so I'm throwing into the ring this data point: Chez Cherie, which offers recreational coooking classes in La Canada (near Pasadena). Owner Cherie Mercer Twohy is an IACP Certified Culinary Professional, and occasional poster at Chowhound.